The long-term objective of this proposal is to develop a mucoadhesive formulation of buprenorphine suitable for sublingual delivery for the treatment of opioid type drug addiction Major drawbacks of currently available dosage forms are related to poor compliance and suboptimal bioavailability of the drug. Buprenorphine undergoes extensive first pass metabolism, therefore salivary washout and involuntary wallowing of the conventional immediate release sublingual tablet would lead to drug loss and inconsistent bioavailability. The use of a mucoadhesive dosage form could address these problems by localizing the drug in the sublingual region, providing sustained release, maximizing compliance by being easy to administer with reduced dose frequency, as well as reducing the potential of drug diversion by the addicted patient. The specific aims of this proposal include the formulation of dosage forms of buprenorphine with mucoadhesive polymers and other excipients using a statistical design, followed by in vitro screening of physicochemical characteristics, mucoadhesive strength and drug release rate, and the in vivo evaluation of the pharmacokinetics of buprenorphine from select formulations in a rabbit animal model. In view of the growing concern with drug abuse and the difficulty to counteract drug related social problems, it is critical to improve the bioavailability, therapeutic value and compliance of drugs already proven to be safe and effective in the treatment of drug addiction, and this can be successfully achieved by utilizing specialized drug delivery systems as the one proposed in this project.